diff --git a/src/aeros_simulation/schema.py b/src/aeros_simulation/schema.py
index 67354e2..958cd7b 100644
--- a/src/aeros_simulation/schema.py
+++ b/src/aeros_simulation/schema.py
@@ -104,8 +104,8 @@ class SimulationData(BaseModel):
     reliability: Optional[dict]
     created_at: datetime
     started_at: datetime
-    duration: int
-    offset:int
+    duration: Optional[int]= 0
+    offset:Optional[int] = 0
 
 class SimulationRankingParameters(EquipmentWithCustomParameters):
     availability:float